How to Choose a Genuine Solar Installer: 15 Checks Before You Pay

Quick answer: Choose an installer with a valid GST registration, registration as a vendor with your DISCOM (needed for the subsidy), a real local office, at least three recent customers you can contact, and a written quote that names exact panel and inverter models. Never pay the full amount upfront.

Rooftop solar demand in India has grown very fast, and so has the number of people calling themselves "solar installers". Many are genuine, experienced businesses. Some are small traders who buy panels, hire daily labour and disappear when something goes wrong. Because a solar system should run for 25 years, choosing the right installer is the most important decision you will make.

Here are 15 practical checks. You do not need technical knowledge to use them.

Part A: Is the business genuine?

1. Check the GST registration

Ask for the installer's GSTIN (a 15-character number). Search it on the official GST portal's "Search Taxpayer" page. Check that:

• The status is Active.
• The legal or trade name matches the name on the quote.
• The state matches where they claim to operate.

A business that refuses to share its GST number or asks you to pay without a GST bill is a red flag.

2. Check DISCOM / subsidy vendor registration

If you want the PM Surya Ghar subsidy, the installer must be registered as a vendor for your electricity distribution company (DISCOM) on the national portal. Ask them to show their registration and confirm it on the portal when you apply. An unregistered installer can still install a system, but you may lose the subsidy.

3. Visit or verify the office

A genuine installer has an office or warehouse where you can see panels, inverters and staff. If they only operate from a phone number and a social media page, be careful. Ask for the address and visit, or at least ask for a live video call from the office.

4. Ask how long they have been in business

Experience matters because problems usually show up after the first monsoon or the first summer. An installer who has been working for three or more years will have dealt with real-world issues like water leakage, wind loads and inverter faults.

5. Speak to at least three past customers

Ask for names and numbers of customers who installed at least a year ago, ideally in your area. Ask them:

• Did the installer finish on time?
• Was the final bill the same as the quote?
• How is the generation compared with what was promised?
• When something went wrong, how fast did they respond?

Part B: Is the quote honest?

6. Insist on exact makes and models

A good quote lists:

• Panel brand, model number and wattage (for example "540 Wp mono PERC, DCR").
• Number of panels.
• Inverter brand, model and capacity.
• Structure material, height and coating.
• Cable brand and size, earthing and lightning arrester details.

Avoid quotes that only say "Tier 1 panels" or "branded inverter". That leaves room to install cheaper equipment.

7. Check the panels are on the approved list

For subsidised home systems, the panels must be made in India using domestic cells (DCR) and be on the government's approved list of models. Ask for the panel datasheet and the DCR certificate.

8. Compare price per kW, not just the total

Divide the total quote by the system size. If one installer is far cheaper than the others, compare the component list carefully. The difference is often a thinner structure, cheaper cables, no lightning arrester, or a smaller inverter.

9. Ask for a written generation estimate

Ask the installer how many units the system should produce per year in your location. A reasonable estimate in most of India is around 1,300–1,600 units per kW per year. Be careful of anyone promising far more, or claiming your bill will become "zero" without looking at your consumption.

10. Get every extra charge in writing

Ask specifically about net meter cost, DISCOM fees, elevated structure, extra cable length, civil work, transport and GST. The quote should say "all-inclusive" or list each extra.

Part C: Will they stand behind the work?

11. Warranties on paper

Make sure you get the manufacturer's warranty documents for panels (product and performance) and inverter, with serial numbers, plus a separate workmanship warranty from the installer covering leaks, loose connections and structure problems.

12. Service and maintenance terms

Ask how many free service visits are included, how quickly they respond to complaints, and what an annual maintenance contract costs afterwards. Get the service phone number and ask who exactly will come.

13. Who does the paperwork?

The subsidy and net metering process involves the portal application, feasibility approval, installation details, inspection and net meter installation. A good installer handles this for you and tells you the steps clearly. Ask who will follow up with the DISCOM if the inspection is delayed.

14. Safe roof work

Ask how they will fix the structure without damaging your waterproofing. Good installers use chemical anchors or proper fasteners with sealing, or ballast-based structures, and seal every drilled hole. Water leakage into the room below is one of the most common complaints after solar installation.

15. A fair payment schedule

A typical fair schedule is a small advance on order, a larger payment when material is delivered to your site, and the balance after installation and commissioning. Never pay 100% before material arrives. Always pay to the business bank account shown on the GST invoice, not to a personal account.

Red flags at a glance

Red flag	Why it matters
"Pay full amount now to lock the subsidy"	The subsidy does not require full advance payment to anyone.
Claims to be "from the government" or the DISCOM	Vendors are private businesses. Government officials do not sell systems door to door.
No GST bill or cash-only deal	No proof of purchase, no warranty claim, no subsidy.
Vague "Tier 1" panel claim with no model number	Lets them swap in cheaper panels.
Promises of zero bill without checking your usage	Shows they have not done a proper design.
Pressure to sign today for a "limited offer"	Genuine installers give you time to compare.

Questions to ask on the site visit

• Where exactly will the panels go, and will any part be shaded during the day?
• What direction and tilt will the panels face?
• Where will the inverter be installed? (It should be in a shaded, ventilated place.)
• How will the cables be routed and protected?
• How will you protect my roof from leakage?
• How will I monitor generation?

A genuine installer will answer these confidently and may even show you a simple layout drawing.

After installation: checks before final payment

1. Count the panels and check the model printed on the back matches the quote.
2. Check the inverter model and serial number match the warranty card.
3. See that the structure is firmly fixed and drilled holes are sealed.
4. Check the earthing pits and lightning arrester are installed.
5. Switch on and check the inverter shows generation.
6. Collect the GST invoice, warranty documents and commissioning report.

Using PeopleList to shortlist

On PeopleList, each solar installer's listing shows exactly what our team has checked, such as phone ownership, GST registration and office location, along with the date of each check. Use it to build a shortlist of three installers, then use the checks in this guide to compare their quotes. Our badges never replace your own checks, but they save you time and help you avoid businesses that cannot even show basic registration.

Comparing three quotes: a worked example

Imagine you receive three quotes for a 3 kW system. Put them side by side in a simple table like this:

	Installer A	Installer B	Installer C
Total price	₹1,85,000	₹2,05,000	₹1,55,000
Panels	Named brand, 540 Wp DCR, model listed	Named brand, 545 Wp TOPCon DCR, model listed	"Tier 1 DCR panels"
Inverter	Named brand, 3 kW, model listed	Named brand, 3 kW, model listed	"Branded inverter"
Structure	Hot-dip galvanised, 1 m height	Hot-dip galvanised, 2 m elevated	Not specified
Earthing and lightning arrester	Included	Included	Not mentioned
Net meter and paperwork	Included	Included	"Extra as per actual"
Workmanship warranty	5 years	5 years	Not mentioned

Installer C looks cheapest, but almost everything that protects you is missing or vague. Installer B costs more because of better panel technology and an elevated structure, which may or may not be worth it for your roof. In this example, A and B are comparable, and the decision should come down to references, service and whether you need the elevated structure.

What a good site survey looks like

A serious installer visits before giving a final quote, or at least does a detailed video survey. During the survey they should:

• Measure the usable roof area and note obstructions like water tanks, staircases and parapet walls.
• Check shade at different times of day, sometimes with a mobile app or shade analysis tool.
• Look at the roof's condition and waterproofing.
• Check your electricity bill, sanctioned load and meter type.
• Decide where the inverter, DC and AC boxes and earthing pits will go.
• Explain the cable route from the roof to the meter.

If an installer gives a "final" price without seeing your roof or bill, the quote is likely to change later.

Understanding the paperwork you should receive

At the end of the project, you should have a file with:

• GST tax invoice with the installer's GSTIN.
• Panel and inverter warranty cards or certificates with serial numbers.
• Panel datasheets and DCR certificate (for subsidy cases).
• Installer's workmanship warranty letter.
• Commissioning or installation report with photos.
• Net metering agreement and inspection report from the DISCOM.
• Subsidy application reference and status.

Keep this file safely. You will need it for warranty claims, if you sell the house, and if any question arises about the subsidy.

After-sales service: the part most people forget

The first few weeks after installation are when small problems appear: an inverter showing an error, the monitoring app not connecting, or water seeping near a fastener after the first rain. Ask before you sign:

• What is your response time for a complaint? Same day, 48 hours, or a week?
• Do you have your own technicians, or do you use contractors?
• Will you handle warranty claims with the panel and inverter manufacturers for me?
• What happens if your company closes? (A good answer is that manufacturer warranties still apply directly.)

Customer references are the best way to judge this. Ask past customers specifically how quickly problems were fixed.

Special cases

Apartments and housing societies

If you live in an apartment, individual rooftop systems are usually not possible. Housing societies can install a system for common areas such as lifts, pumps and corridor lighting, which reduces maintenance charges for everyone. These projects need a society resolution and an installer experienced with larger systems.

Shops and small businesses

Commercial tariffs are often higher than residential ones, which can make solar pay back faster. However, the residential subsidy does not apply, and approval rules differ. Ask installers for references from similar businesses.

Old or weak roofs

If your roof leaks or has cracks, fix and waterproof it first. Removing a solar structure later to repair the roof costs time and money.

Frequently asked questions

Should I buy panels myself and only hire an installer?

It is possible, but then warranty claims and responsibility become unclear. Most homes are better off with one installer responsible for the complete system and paperwork.

Are big brands always better than local installers?

Not always. A well-established local installer with good references and fast service can be better than a big brand that sends a sub-contractor. What matters is equipment quality, workmanship and after-sales service.

How long does installation take?

The physical installation of a home system usually takes one to three days. The full process, including approvals, inspection and net meter, can take a few weeks depending on your DISCOM.